WASHINGTON — After more than a month of talks, and amid complaints about the nature of the investigation itself, President Trump's advisers have not committed to him testifying in the investigation involving Russian interference in the 2016 election and claims that the president may have tried to obstruct justice.

Trump told reporters on Jan. 24 that he was "looking forward" to testifying under oath, perhaps in "two or three weeks," but added that it was "subject to my lawyers and all of that "

Two weeks later, Trump's team has yet to sign off on a deal, and is raising questions about Special Counsel Robert Mueller's investigation after a newly declassified memo from the Republican chairman of the House Intelligence Committee.

"The professional and active discussions between the (special counsel) and the president’s personal lawyers regarding how and under what terms information will be exchanged are understandably private," said a statement put out by the White House.

If Trump ultimately refuses to testify, Mueller would have to decide whether or not to subpoena the president.

For months, Trump aides have claimed they have given Mueller's office an unprecedented number of documents.

Trump and his team have also raised concerns about the investigation itself in the wake of a release of a memo by Rep. Devin Nunes, R-Calif., chairman of the House Intelligence Committee.

The memo claims the FBI obtained a warrant on Trump campaign aide Carter Page based on a dossier compiled by Christopher Steele, a former British intelligence agent working for a company hired by Democratic presidential candidate Hillary Clinton. Democratic lawmakers, and even the Nunes memo, say Steele's research was just one piece of evidence used to support the surveillance warrant.

Claiming vindication from the memo, Trump tweeted that leaders of the FBI and the Justice Department "have politicized the sacred investigative process in favor of Democrats and against Republicans."

Democrats such as Rep. Adam Schiff, D-Calif., top Democrat on the House Intelligence Committee, said the Nunes memo is false, but Trump may use it to justify firing Mueller and not testifying.

Since late December, talks between Trump and Mueller lawyers have tried to agree on a time limit for an interview, where it would take place and the scope of questioning.

Testimony by other presidents

Trump's team has pointed out that President Ronald Reagan answered written questions during the Iran-Contra investigation.

President Bill Clinton, meanwhile, testified to a grand jury via video from the White House during special counsel Kenneth Starr's investigation into Clinton's investment in an unsuccessful land deal in Arkansas that expanded to include his extramarital relationship with White House intern Monica Lewinsky.

Robert Ray, who succeeded Starr as the independent counsel, said Tuesday it was unrealistic to expect that negotiations for the president’s testimony to be completed as quickly as Trump and other wanted.

“There are going to be skirmishes along the way,” Ray said. “I suppose he could raise the Nunes memo as an argument that the investigation is somehow biased against him. But I think too much water has passed under that bridge for that argument to be effective."

Ray said it's likely that "what you are seeing are skirmishes that generally precede some sort of an agreement."

While there are reasons Trump may want to skip an interview — "there is no point in walking in and providing more information to the special counsel and risk the possibility of making false statements" — the president and his team must also take public reaction into account, Ray said.

"There are major political considerations here, and the public may demand and expect that the president submit to an interview,” Ray said.

Bruce Udolf, who served as an associate independent counsel during the Whitewater investigation, said if Trump attempts to use the Nunes memo as an excuse not to testify, the president would be "asking for a subpoena."

"This memo has no credibility at all," Udolf said. "At least Clinton had the sense of arranging to testify from the White House to avoid the indignity of going to the courthouse.

"Trump seems to think that the rules don't apply to him," Udolf said. "If he pushes it, his options run out. And I'd drag his fanny before the grand jury."